Valve rotator and lock



March 7, 1961 A. c. SAMPIETRO 2,973,753

VALVE YROTATOR AND LOCK Filed May 15, 1958 2 Sheets-Sheet 1 mania? v Ac/zil/e; Sam 01am b 57 W M 8 @2295 I llllllll \\ww m .m I 1 1 March 7, 1961 A. c. SAMPIETRO 2,973,753

VALVE ROTATOR AND LOCK Filed May 15, 1958 2 Sheets-Sheet 2 Achilles Samplezro W #WQM9W 57 7 HZLZLHE ilnited States Patent VALVE ROTATOR AND LOCK Achilles C. SampietrmDetroit, Micln, assignor to Thompson Ramo Wooldridge Inc., a corparation of Ohio Filed May 15, 1958, Ser. No. 735,602

12 Claims. (Cl. 123-9ii) rotating engine valves since cyclic operation and rota-.

tion of the valves during the course of engine running assists in eliminating valve burning, as well as wearing, pitting and stem-galling and scoring. 7

It is an important aim of the present invention to a reduced number of simplified parts which can be manufactured and fabricated with substantial economies.

Another object of the invention lies in the provision of'a novel combination of retaining means and spring provide an engine valve rotator construction formed of l means functioning in cooperation with the valve return spring to transmit the force therefrom to the valve stem during cyclic operation and effect rotation ofthe valve.

Another object of the invention is to provide a valve rotating arrangement wherein coiled displaceable spring means are receivable in a grooved valve stem and maintained therein by a shaped valve spring retainer member, the coiled spring means functioning to rotate the valve and lock the retainer means in an essentially axially immovable position during cyclic operation of the valve.

Other objects and advantages of the invention will become more apparent during the course of the following description, particularly when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

Figure 1 is a fragmentary view showing valve spring retaining means according to the principles of the present invention applied to the poppet valve assembly of an internal combustion engine and with parts broken away and with parts shown in cross-section to illustrate the positioning of the components when the valve is in the closed position during cyclic operation thereof;

Figure 2 is a view similar to Figure 1, and showing the parts when the valve is in an open position;

Figure 3 is a detail sectional view of the retaining means and spring locking means therefor;

Figure 4 is a vertical sectional view takensubstantially along the line IV--IV of Figure 3;

Figure 5 is a detail sectional view of a modified form of the invention showing the use of cap means to facilitate valve rotation;

Figure 6 is a detail sectional view of another form of .the invention showing a somewhat different configuration of retainer member; and

Figure 7 is a sectional view of the spring means of Figure 6 coated to improve the characteristics thereof.

2,973,753 Patented Mar. 7, 1961 Briefly stated, the novel structure of this invention comprises a retainer member formed with a generally axially extending collar portion adapted to be arranged in radially spaced and encircling relation to the valve stem. A shaped groove is formed in the valve stem and receivable within said groove is spring means preferably comprising a plurality of coiled loops acted upon by the collar. portion of the retainer member. The coiled loops are disposed generally vertically when the valve is in its closed position, and during axial movement of the valve in response to varying loads, the coiled loops are compressed and displaced vertically to effect rotation of the valve with respect to the retainer member. Numerous other features of the present invention will be presented in the description now .to follow.

Referring now to the drawings, the valve spring retaining means of this invention, generally indicated by the numeral 10, comprises a retainer member 11 constructed to surround a valve stem 12 having a shaped groove 13 formed in the tip end 14 thereof and receiving spring means 15. r

The groove 13 in the stem 12 is generally conical, and accordingly tapers radially inward toward the cap or tip portion 14 of the stem. Between the groove 13 and tip portion 14 is a -generally rounded shoulder portion 16 bottoming the spring means 15. Particularly good results have been obtained with the groove and shoulder construction shown; however, the conventional straight wall groove may be found in certain applications productive of satisfactory results.

The retainer member 11 is preferably essentially circular in plan, and in the arrangement of Figures 1 to 5, is shaped generally centrally thereof with a substantially conical collar portion 17 connecting with a generally cylindrical neck portion 18 in gripping contact with the valve stem 12 axially inwardly of the groove 13 therein. Connecting with the collar portion 17 of the retainer 11 and extending radially outwardly therefrom is a base'or flange portion 19.

The spring means 15 is bottomed along a portion of its circumference by the rounded shoulder 16 oftthe stem tip end 14 and along another portion of its circumference by inner surface 20 of the conicalcollar portion 17 of the retainer 11. While the coils forming the spring means 15 are displaced from a generally vertical plane to effect valve rotation as will-be later described in detail, the spring means 15 is held against substantial axial displacement or movement by the wedging action of the conical collar 17 and shoulder 16. Further, the spring means 15 effectively restrains the retainer member 11 against major axial movement with respect to the stem 12 and thereby locks the retainer in the position shown in the drawings.

The spring means 15 conveniently comprises any selected plurality of helically or toroidally looped coils 21, or a helically wound coil spring having a multiplicity of individual coils relatively closely spaced with respect to one another so that the helix angle of the individual coils is sufiiciently small to permit the spring means 15 to transmit forces in a direction transverse to the longitudinal axis of the spring. Thereby, normal return spring forces are transmitted from the retainer member 11 to press the spring means 15 against the rounded shoulder 16 and displace the individual coils 21 into a generally inclined position and effect aratcheting or free wheeling effect to insure relative rotation between the valve stem 12 and retainer member 11. a

As is shown in Figures 1 and 2, the valve spring retaining means 10 of the present invention may be assembled in an internal combustion engine or the like.

i In the embodiment shown, an engine part is indicated at 22 which provides a port designated at P having a valve opening 23 presenting a beveled valve seat 24 regulated by the beveled seating surface 25 of a valve head 26 carried on the end of the valve stem 12. The stem is slidably carried in an engine part 27 by means of a valve stem guide 28. A valve return spring 29 has one end 30 bottomed against the engine part 27, and an opposite end 31 of the spring 29 bottomed against the base or flange portion 19 of the retainer member 11. Rocker arm 32 or other means such as a tappet induces axial movement of the valve stem 12 in the manner well known to the art.

To assemble the novel device of this invention, the retainer member 11 is positioned with the generally cylindrical neck portion 18 thereof in axial alignment with the tip end 14 of the stem 12, and is thereupon moved axially along the valve stem until the flange portion 19 of the member 11 is spaced inwardly of the rounded shoulder portion 16 of the stem end 14. Thereturn spring 29 is compressed at this time, and the spring means 15 is passed over the stem end 14 and lodged in the groove 13 and against the rounded shoulder portion 16 of the stem end 14. The retainer member 11 is thereupon moved axially in the opposite direction to firmly wedge the spring means 15 in a preloaded condition against the shoulder portion 16 by action of the inner surface 20 of the conical collar portion 17 of the spring retainer 11. It may thus be seen that the spring means '15 restrains the retainer member 11 against substantial axial displacement, and inadvertent dislodgement of the retainer 11 from the stem 12 is essentially impossible. Further, the retainer member 11 cooperates with the rounded shoulder portion of the valve stem to maintain the spring means in an essentially immovable axial location upon the valve stem 12.

As indicated, the individual loops 21 of the spring means 15 are disposed in a substantially vertical position when the valve stem 12 is in the closed position of Figure 1. Upon the application of an axial load to the stem 12 by action of the rocker arm 32, which compresses the return spring 29, the rounded shoulder portion 16 cooperating with the inwardly tapering surface 21] of the re tainer collar 17 compresses the spring means 15 into gen erally the condition of Figure 2. During said compression the individual loops 21 of the spring means tip or incline vertically and in so doing transmit forces to the valve stem transverse to the longitudinal axis of the spring. Thus, a ratcheting or free wheeling effect is obtained with the result that relative rotation occurs between the valve stem 12 and the retainer member 11 after the valve head 26 has moved from the seat 24-. While success is obtained with a smooth surface 20 on the collar portion 17, particular conditions may indicate the desirability of employing asymmetrical serrations on either the valve stem conical groove 13 or on the inner surface 20 of the collar 17.

It may be found upon occasion that the force exerted by the return spring 29 during valve opening is not sufiicient to compress the spring means 15 to the degree required for valve rotation, and accordingly, the arrangement shown in Figure may be advantageously employed. Rotation of the valve stem 12 is accomplished by unloading the spring means 15 either partially or totally, and means effective for this purpose comprises a cap member 33 in combination with the elements earlier disclosed. In the form shown, the cap member is shaped to include a generally circular body portion 34 having a central recess or cavity 35 therein sized to snugly receive the tip end 14 of the valve stem 12, and additionally of a depth to provide a clearance space 36 calculated to allow the necessary unloading. The body portion 34 of the cap member 33 further includes a radially outwardly extending flange or rim portion 37 hearing along its lower surface 38 against upper surface 39 of the flange portion 19 of the retainer member 11. The rocker arm 32 normally bears against the cap member 33 generally centrally thereof along an essentially flat upper surface 40.

The spring means 15 is located against the shoulder portion 16 of the stem tip end 14 in a preloaded condition. Thus, at essentially the same time that the return spring 29 exerts a force against the retainer member 11 to compress the spring means 15, an axial load by the rocker arm 32 against the cap member 33 moves the retainer member axially and thereby a lesser load of compression is applied to the spring means 15 and said means is unloaded to effect the desired rotation of the valve stem. As will now be appreciated, the clearance space 36 is calculated to permit a predetermined amount of axial travel of the cap member 33 sufiicient to allow the spring means 15 to be unloaded and rotation of the valve stem 12 effected. It may further be seen that the cap member 33 transmits an axial force opposing the force of the return spring 29 whereby the spring means 15' is loaded by the return spring and unloaded by the cap member 33. The loading and unloading described, in combination with the inherent vibrations of the engine and other factors, has been found sufficient to provide the desired valve rotation with the known result of longer valve life.

The use of certain valve spring retainers and valve rotators has induced valve stem wear, particularly when the stem was formed of relatively soft materials, and there is now provided a structural arrangement operating in accordance with the principles of this invention which reduces valve stem Wear to essentially an absolute minimum. Referring now to Figures 6 and 7, there is shown a retainer member 41 and spring means 42 of somewhat different form effective for this purpose.

The retainer member 41 includes a radially outwardly extending base or flange portion 43 bottoming the return spring 2% as indicated at 44, and a radially inwardly curved collar portion 4-5 spaced from the valve tip end 14 and maintaining the spring means 42 against the rounded shoulder portion 16 of the valve stem tip end. It is to be noted that in this form of the invention the collar portion 45 is free of contact with the valve stem, and accordingly, no Wear occurs by movement therebetween.

To further reduce valve stem wear, the spring means 42 carries on at least its outer diameter a layer or coating 46. The coating or sleeve is selected to provide the necessary friction when in contact with the valve stem tip end and retainer member, and yet at the same time, to not induce substantial wear on the parts contacted. Further, since the valve stem 12 becomes heated during cyclicoperation, the coating or sleeve material must he possessed of substantial heat resistance. A number of materials are so characterized, and compositions found by applicant to be particularly effective are woven asbestos, molded silicone or certain sintered materials. These may be applied to the spring means 42 by methods known to the art. The action of the spring means 42 in locking the retainer member 41 and effecting rotation of the parts is essentially the same as in the earlier described forms of the invention, and by provision of the generally dome-shaped retainer member 41 spaced from the valve stem and the coated spring means 42, valve stem wear is markedly reduced without sacrifice in the effectiveness of the spring retainer and valve stem rotator. Further, by the particular dome shape of the retainer member 41, relatively high stresses associated with prior art structures are substantially eliminated.

It may be seen from the foregoing that applicant has provided a valve spring retainer construction comprising a minimum number of readily facricated parts functioning additionally to effect rotation of the valve stem to reduce wear at the head thereof. The retainer member in either form disclosed may be produced by stamping operations at minimum cost. Further, since there is no point contact between the retainer member and the valve stem, wear on the valve stem is kept to a minimum.

spring means." 1 a e M I 1 E 5. I Ini combination withn-a -"poppet ,valve jhaving a groovedstem ajnd a return spring therefor, a retainer s 5 However, by the arrangement of Figures 6 and 7, valve stem wear is rendered even more remote. In the functioning of the device of this invention over-stressing of the spring means is an unlikely occurrence, and it is to be noted that the spring means functions in a dual manner to maintain the spring retainer in its proper position with respect to the valve stern, and also by being pre loaded and compressed during cyclic operation of the valve, rotation of the valve stem is readily effected at substantial economies. 7

It is to be understood that the forms of the invention herein shown and described are to be taken as the preferred embodiments of the same, and that various changes in the size, shape and arrangement of parts may be effected without departing from the spirit of the invention or the scope of the subjoined claims.

I claim as my invention: I

1. In combination with a poppet valve having a grooved stem and a return spring therefor, resilient means normally located entirely in the stem groove, and a retainer member in pressing contact with the return spring and provided with a conically shaped collar portion having an essentially smoother inner diameter converging axially inwardly from the stemgroove bearing against the resilient means by action of the return spring and maintaining said resilient means in the stem groove.

2. In' combination with a poppet valve having a grooved stern and areturn spring therefor, coiled spring means located 'in the stem groove, and a retainer memberhaving a base flange in pressing contact with the return spring and a radially inwardly directed collar portion having essentially the same wall thickness as the base.

flange bearing againstthe spring means and restrained against substantial axial movement relative to the valve stem by action of the spring means, said collar portion connecting at one end with the base flange and being substantially radially outwardly spaced at the opposite ,end from the valve stem to prevent wear therebetween during valve operation.

' 3. In combination with a poppet valve having a grooved stem anda return spring therefor, coiledspring intimate'contact with the valveistem and axially spaced from thevgroove therein, said collar portion maintaining v the"spring me'ans in the stem groove and itself being restrained by;- the spring means against substantial axial movement relative to the valve stems a g 4. In combination with a poppet valve having a pressing contact with thereturn spring and a radially jinwardly directed collarportion,having an essentially smooth and uninterrupted inner diameter bearing against ,the spring meansand restrainedjagainst substantial axial in the absence of an axial load upon the valve stem and tate the valve stem.

6. Valve Spring retaining means, comprising a retainer member adapted to surround a grooved valve stem and provided with an inwardly turned collar portion of essentially uniform wall thickness throughout radially spaced from'the valve stem, and coiled spring means positioned in the stem groove in contact with the retainer collar portion and preventing substantial axial movement of the retainer member.

7. Valve spring retaining means, comprising a generally dome-shaped retainer member provided with a radially outwardly directed flange portion and a radially inwardly turned collar portion,'the wall thickness of the collar portion corresponding essentially to the wall thickness of the flange portion, and a coiled spring surrounding the valve stem located in the groove therein and compressed by the collar portion during axial movement of the valve stem to efiect rotation of the valve.

8. Valve spring retaining means, comprising a generally dome-shaped retainer member provided with a radially outwardly directed flange portion and a radially inwardly turned collar portion having an essentially smooth and uninterrupted inner diameter, and a coiled spring surrounding the valve stem located in the groove therein and compressed by the collar portion during axial movement of the valve stem to efifect rotation of the valve, said spring carrying on the stem contacting surfaces thereof a layer of heat resistant material. 1

9. In combination with a poppet valve havinga grooved stem and a return spring therefor, resilient means normally located entirely in the stem groove, a retainer member in pressing contact with the return spring and g collar portion being inwardly turned and being of essenmeans located in the stem groove, and aretainer mem 7 her having a collar portion radially spaced from the'stem groovebearing against the spring means and defining with I the grooved stern a generally triangularly'shaped annular recess receiving, the spring means," and a neck portion in movement relative ,to ,the valve'estem by action of the a member" in theform of a sheet metal stamping having a tially uniform wall thickness throughout and a cap member seated upon the valve stem and return spring and unloading the. resilient means to eifect rotation of thevalve. v

10. A structured the character defined in claim 2, in which the spring means carries along the outer diameter thereof a coating of substantial wear resistance and which provides friction with the valve stem without inducing substantial wear.

11. In combination with a poppet valve havingga against the resilient means by action of the' return spring and, maintaining said coiled spring means'in the stem groove.

i 12. Valve spring retaining means, comprising a retainer member adapted to surround a grooved valve stem and provided with an inwardly turned collar portion radially spaced from thevalve stem, and coiled spring means positioned :in the stem groove in contact with the retainercollarj portion and preventing substantial axial movement of the retainer member.

" References Citetl'iin thelile of this patent f umrnn STATES PATENTS g gnbnontsut u 'Aug. 14, 1956 grooved stem and a return spring therefor,,coiled spring means located in the stem groove, and a retainer mem-- her in pressing contact with the return spring and pro- J vided' with a conically shaped collar portion bearing g Aiken July 1, 19585 7 I2,844,134 Sietman "July 22, 1958 

